1. Field of the Disclosure
The present disclosure relates generally to fiber optic cables, and in particular relates to crush-resistant fiber optic cables.
2. Technical Background
Conventional fiber optic cables include optical fibers that conduct light for transmitting voice, video and/or data. The construction of fiber optic cables should preserve optical performance when deployed in the intended environment while also meeting the other additional requirements for the environment. Mechanical requirements or characteristics, such as crush performance, permissible bend radii, temperature performance, and the like, are preferred to inhibit undesirable optical attenuation or impaired performance during installation and/or operation within the space. In addition to the mentioned requirements, riser and/or plenum spaces may require a ruggedized design for meeting the demands of the space.
In many applications, it is desirable for a fiber optic cable to include a plurality of optical fibers. With the increased demand for optical communications, there has been a corresponding demand to increase the number of optical fibers, i.e., the fiber count, of a fiber optic cable. By increasing the fiber count of a fiber optic cable, a single fiber optic cable is able to support additional optical communication channels.
Fiber optic cables employing a plurality of multimode optical fibers are often used in data centers, where the transmission length is relatively short compared to long-haul distances. Because data centers have limited space in which to deploy fiber, it is preferred that the multi-fiber fiber optic cables be as small as possible (i.e., have as small a diameter as possible). Small-diameter multi-fiber fiber optic cables have been fabricated using conventional optical fibers. However, to make the cable diameter small, the strength elements (e.g., a central strength element) are typically eliminated.
Additionally, fiber coatings that provide protection may be eliminated to increase fiber density. For example, 250-micron fibers may be used instead of 900-micron tight buffered fibers. This makes the conventional multi-fiber fiber optic cable more prone to damage due to crushing. When subjected to particular types of crushing forces, such as being pressed into by other equipment, stepped on, or objects with sharp features being placed atop or against the cable, the multiple optical fibers within the cable are pushed against one another and incur relatively sharp bends. This sharp bending leads to attenuation or even the complete loss of signal traveling in the optical fibers.
Therefore, there is a need in the art multi-fiber fiber optic cables having a relatively small diameter while also being resistant to crushing forces that cause strong bends in the optical fibers.